Visibility issues in trucks

Jun 2018

Vehicle Technology

One of the most challenging tasks undertaken by truck drivers is turning the vehicle in the direction opposite from the driver’s seat in city traffic. When doing so, the driver has to look ahead and observe the traffic lights, signs, cross traffic and oncoming traffic at the same time as well as look to their side to check for pedestrians and cyclists. What’s more, the traffic situation can change in a matter of seconds – and cyclists and pedestrians are not always aware that truck drivers may not be able to see them at all because they are in the vehicle’s blind spot.

While a quick glance over one’s shoulder through the driver’s window in a truck gives drivers an extensive view, all drivers can see when they look back over their shoulder is the back wall of the cabin in the cargo area. Of a 360-degree view (in theory), the cargo area alone takes away around a third. The driver therefore generally has to use the exterior mirrors to ascertain the situation in the areas that are not visible. In addition to mirrors, camera monitor systems are becoming increasingly common today, although one has to think carefully about where best to position these systems. For example, can an existing monitor in the dashboard be used? Or would it make more sense to position the monitor close to the mirrors so that drivers glance at the side facing away from them when they need to ascertain the situation from this area? Other questions concern the brightness of the monitor and when the monitor displays which signal.

Due to the numerous collisions between cyclists and trucks that are undertaking turning maneuvers, intensified activities aimed at improving visibility from inside trucks are currently under way in the United Kingdom. The aim is to reduce the blind spot from the vehicle itself by moving the lower edges of the windshield much further down. From the point of view of accident researchers at DEKRA, among others, this is to be welcomed in principle. But it is important to remember that these activities relate to a design specification – or, more specifically, “specifications regarding the lower edges of windshields.” A performance requirement would undoubtedly be more constructive. Why is this? A design specification prevents innovative solutions because the design is stipulated. A performance requirement focuses on the end result being achieved – the type of measure selected does not play any role in the process. Generally speaking, one has to first be clear about what the driver must be able to see in front of and next to their vehicle. During the design phase, the lower edges of the windshield can be lowered or another suitable measure can be implemented.

A turning assistance system that detects the presence of people such as that introduced by Mercedes-Benz can also make a significant contribution to preventing accidents when vehicles are turning in the direction of the passenger side. This system is multi-stage: If a cyclist or pedestrian stops in the warning zone, the LEDs in the A-pillar on the passenger side light up yellow in the shape of a triangle. If the system detects a collision risk, the LEDs light up red with a higher luminosity and a warning signal sounds from the right side of the vehicle via a radio system speaker. Furthermore, when the vehicle turns, the sensors can detect a stationary obstacle such as a traffic light or lamp in the trajectory curve of the truck. This prevents collisions not only on public roadways but also when drivers are maneuvering into, for example, parking spaces. This extensive driver assistance is available over the truck’s entire speed range from when it is stationary – at a traffic light, for example – all the way to the maximum authorized speed. This is a system that truly helps to prevent serious accidents.

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